I am rendering a template by streaming data from a Flask view. When I do not use url_for, the page works correctly. If I add url_for, I get RuntimeError: Attempted to generate a URL without the application context being pushed. This has to be executed when application context is available.
I tried the answer in Flask.url_for() error: Attempted to generate a URL without the application context being pushed, but I still get the error after adding app.config['SERVER_NAME'] = 'localhost:5000'
How can I generate urls in the streamed template, preferably without setting SERVER_NAME or hardcoding the path?
<!doctype html>
<html>
<head>
<link rel="shortcut icon" href="{{ url_for('static', filename='favicon.png') }}">
</head>
<body>
{% for number in data %}
<script>
console.log(JSON.parse({{ number|tojson }}));
</script>
{% endfor %}
</body>
</html>
from flask import Flask, json
app = Flask(__name__)
def stream_template(template_name, **context):
app.update_template_context(context)
t = app.jinja_env.get_template(template_name)
rv = t.stream(context)
rv.enable_buffering(5)
return rv
@app.route('/')
def main():
def generate():
for number in range(10):
yield json.dumps(number)
return Response(stream_template('index.html', data=generate()))
if __name__ == '__main__':
app.run(debug=True)
